1. Field of the Invention
The present invention relates to an image-taking apparatus that includes an imaging device and forms a subject image on the imaging device thereby generating image signals.
2. Description of the Related Art
Image-taking apparatus so-called digital cameras have an imaging device such as charge-coupled device (CCD) type or metal-oxide semiconductor (MOS) type and captures subject light entering through a shooting lens with the imaging device to generate image signals. Such digital cameras have become rapidly widespread in recent years. Similarly to cameras that perform shooting by use of photographic films, digital cameras enable a user to select a condition for exposure, which is a combination of shutter speed and aperture suitable for subject brightness or user's preference. Moreover, digital cameras can be made smaller in size and lighter in weight as compared to conventional cameras using photographic films.
Since digital cameras have become smaller and lighter, how to deal with camera shakes has come into focus as one of serious problems because a light and small digital camera is prone to move at the time of shooting thereby causing camera shakes.
In order to address problems related to camera shakes, various attempts have been proposed (see Japanese Patent Application Publications No. 7-281239 and No. 5-7328 for example).
Japanese Patent Application Publication No. 7-281239 proposes a technique for reducing blurriness of a subject image. In this technique, a blur correction device is employed and a maximum shutter speed (per sec.) is set beforehand in view of the limit of performance of the blur correction device that is driven while slow-sync shooting is performed. To reduce blurriness of a subject image, a shutter speed to be used at the slow-sync shooting is made shorter than the maximum shutter speed. Meanwhile, Japanese Patent Application Publication No. 5-7328 proposes a technique for reducing blurriness of a subject image for movie shooting by detecting movements of the subject image.
However, the technique of Japanese Patent Application Publication No. 7-281239 has such a drawback that, because the maximum shutter speed to be used when the blur correction device is driven is determined by the limit of performance of the blur correction device, a range of selectable conditions for exposure is limited by the driving of the blur correction device. Also, the technique of Japanese Patent Application Publication No. 5-7328 has such a drawback that blurriness of a subject image in one field corresponding to a still image cannot be corrected because this technique is configured to correct a blur generated between fields in a moving image.
The present invention has been made in view of the above circumstances, and provides an image-taking apparatus capable of reducing blurriness of a subject image while providing a wide range of conditions used to determine exposure.